Size-dependent ecotoxicity of barium titanate particles: the case of Chlorella vulgaris green algae

Abstract

Studies have been demonstrating that smaller particles can lead to unexpected and diverse ecotoxicological effects when compared to those caused by the bulk material. In this study, the chemical composition, size and shape, state of dispersion, and surface's charge, area and physicochemistry of micro (BT MP) and nano barium titanate (BT NP) were determined. Green algae Chlorella vulgaris grown in Bold's Basal (BB) medium or Seine River water (SRW) was used as biological indicator to assess their aquatic toxicology. Responses such as growth inhibition, cell viability, superoxide dismutase (SOD) activity, adenosine-5-triphosphate (ATP) content and photosynthetic activity were evaluated. Tetragonal BT (~170 nm, 3.24 m(2) g(-1) surface area) and cubic BT (~60 nm, 16.60 m(2) g(-1)) particles were negative, poorly dispersed, and readily aggregated. BT has a statistically significant effect on C. vulgaris growth since the lower concentration tested (1 ppm), what seems to be mediated by induced oxidative stress caused by the particles (increased SOD activity and decreased photosynthetic efficiency and intracellular ATP content). The toxic effects were more pronounced when the algae was grown in SRW. Size does not seem to be an issue influencing the toxicity in BT particles toxicity since micro- and nano-particles produced significant effects on algae growth.

The effect of lead on the growth, content of primary metabolites, and antioxidant response of green alga Acutodesmus obliquus (Chlorophyceae)

“…(Poskuta et al 1996;. Growth inhibition in microalgae is Yang et al 2014;Polonini et al 2015). The suppression of growth by heavy metals was also observed in experiments performed on C. vulgaris cultures treated with Cd, Pb, and Cu (Bajguz 2011;PiotrowskaNiczyporuk et al 2012).…”

“…Algae contain also several enzymatic (e.g., superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR)) and non-enzymatic (e.g., glutathione, ascorbate) antioxidant defense systems protecting cells from oxidative damage (Bajguz 2011;Piotrowska-Niczyporuk et al 2012;Polonini et al 2015), which generally results at elevated levels of metals. SOD constitutes the primary line of defense in this system, as it dismutates superoxide radicals to H 2 O 2 .…”

“…Elevated contents of heavy metals in water bodies elicit deleterious impact on microalgae, which are the primary producers at the base of the aquatic food chain (Zhou et al 2011;Rajamani et al 2014). They are one of the first groups to be affected by heavy metal contamination, and therefore, they provide important information for predicting the environmental impact of pollution (Yang et al 2014;Polonini et al 2015). Microalgae can sequester metal ions because of the presence of cell wall, which is composed of a fiber-like structure and amorphous embedding matrix of various polysaccharides (Hu et al 2001;Peña-Castro et al 2004;Javanbakht et al 2014).…”

Pterodon emarginatus oleoresin-based nanoemulsion as a promising tool for Culex quinquefasciatus (Diptera: Culicidae) control

“…Nano-size may enhance toxicological effects, when compared to bulk material. Thus, evaluation of ecotoxicological impact of nanostructures should be encouraged, including aquatical toxicology using C. vulgaris as biological indicator [50]. Complexes of carbon nanotubes-diuron increased toxicity of the herbicide against C. vulgaris [51].…”

Synthesis and larvicidal activity of indole derivatives against Aedes aegypti (Diptera: Culicidae)

“…The use of microalgae in ecotoxicological tests is accepted and well defined internationally, and it is described and regulated by various international protocols, including those reported by the United States Environmental Protection Agency (USEPA) and the Organisation for Economic Cooperation and Development (OECD, ) Test Nº 201: Freshwater alga and cyanobacteria, growth inhibition test. Chlorella vulgaris and Scenedesmus obliquus are important green microalgae in aquatic ecosystems that are considered as bioindicators in ecotoxicological studies because they have a short life cycle, are easily cultivated in laboratories and are sensitive to toxic compounds (Polonini et al, ).…”